Sears offers the Serta Perfect Sleeper Taryn Super Pillow Top II Queen Mattress, model no. 500206243-1050, for $449.99. Coupon code "SEARS5OFF50" drops it to $444.99. With $69.99 for shipping, that's $680 off list and the lowest total price we could find. It features foam and gel foam layers, carbon steel coils, and a double-beam foundation.
Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.